1. Field of the Invention
The present invention relates to the touch-control technology, and more particularly to a touch screen and a coordinate positioning method.
2. Related Art
Recently, due to the rapid development of the technology, handheld devices, such as a smart mobile phone, a digital personal assistant (PDA), a global position system (GPS) and the like, have become more and more popular. Because touch screens are used in the above-mentioned devices, the technology of the touch sensor becomes very important. In the prior art, the typically used touch sensor is a resistive sensor. This resistive sensor has to sense the coordinate on the screen according to the pressure. A liquid crystal display is usually used in the handheld device, and the resistive sensor further has to be overlapped with the liquid crystal display. So, when the liquid crystal display presses the resistive sensor, the liquid crystal display is correspondingly pressed. After a long period of time, the liquid crystal display may be thus damaged. In addition, the resistive sensor has the lower resolution, and the coordinate often cannot be positioned precisely.
In the prior art, another touch sensor corresponding to a capacitive touch panel is also adopted. At present, the capacitive touch panel is widely applied to the touch screen of the handheld device. However, four layout layers have to be adopted in the circuit layout of the touch board of the conventional capacitive touch panel. FIG. 1 is a cross-sectional view showing a structure of a conventional capacitive touch panel. Referring to FIG. 1, the capacitive touch panel includes a Y-axis sensing layer 101, an X-axis sensing layer 102, a grounding layer 103 and an electronic component layer 104, wherein electric elements, including control ICs, resistors, capacitors, and the like, connected together may be disposed on the electronic component layer 104. FIGS. 2 and 3 respectively show the structures of the Y-axis sensing layer 101 and the X-axis sensing layer 102 of the conventional capacitive touch panel. Referring to FIGS. 2 and 3, the Y-axis sensing layer 101 and the X-axis sensing layer 102 respectively include multiple parallel sensing electrodes X00 and Y00.
In addition, the conventional capacitive touch panel further has still another structure, such as an indium tin oxide (ITO) glass structure with six layers. FIG. 4 is a cross-sectional view showing a conventional capacitive touch panel with the indium tin oxide (ITO) glass structure. Referring to FIG. 4, the first layer 401 is a silicon dioxide (SiO2) layer for protecting a Y-axis sensing layer. The second layer 402 is the Y-axis sensing layer. The third layer 403 is a glass layer. The fourth layer 404 is an X-axis sensing layer. The fifth layer 405 is a silicon dioxide layer for protecting the X-axis sensing layer. The sixth layer 406 is a noise shielding layer for shielding the noise.
However, the printed circuit board or the indium tin oxide (ITO) glass structure has to be configured into a two-dimensional plane so that the conventional capacitive touch panel may be applied to the sensing over the two-dimensional plane. Thus, the manufacturing procedure is complicated, and the cost requirement also becomes higher.